This invention concerns washing machines and more particularly vertical axis clothes washing machines of the type in which the washing action is achieved by agitation of the clothes-washing solution load.
In such washing machines, the agitation washing action is achieved by the resultant rubbing movement of the articles to be washed against other surfaces of the fabric or against the interior surfaces of the basket or agitator.
Accordingly, for effective and uniform washing action, all of the clothes surfaces should be evenly exposed to such rubbing action.
An additional feature of the agitator is to enable freeing of the dirt particles and scum to enable settling out to the lower region of the tub. Similarly, the circulation of the lint formed at the inner face of the edge of the clothes enables recirculation flow of wash water to filter out the lint particles during the wash cycle.
It has long been recognized that these requirements are very admirably met by a so-called toroidal circulatory movement of the clothing or other fabric articles to be washed, as discussed for example in U.S. Pat. Nos. 3,987,651; 4,018,067; and 3,285,040. Such toroidal circulation causes the articles to move downwardly along the agitator post (in those machines utilizing an agitator for the achievement of agitation) and thence outwardly along the receptacle bottom, up the basket sides and thence to the center region to complete the movement cycle. This achieves the proper uniform disposition of the article surfaces to the washing/rubbing action, reduces tangling, yields a smooth agitator action which reduces the drive torque requirements, and prevents excessive rubbing or pulling of the clothing surfaces.
The achievement of such toroidal movement has heretofore been primarily achieved by the establishment of a radially outward flow of the wash water in the lower region of the basket, this flow carrying with it the fabric articles. While satisfactory for relatively fluid clothes-water mixes, as the clothes load increases, the fluidity of the mixture decreases to the point where the mixture no longer behaves as a liquid and hydraulic forces available to circulate the articles are insufficient to establish the circulatory movement of the articles themselves. The load then tends to stagnate, causing excessive wear on some of the surfaces of the articles and deficient washing action on others.
Another difficulty encountered in such machines including an agitator with radially extending vanes to establish such water flow is the so-called chording action in which the clothing articles are drawn or pulled radially inward upon draping engagement with the edges of the radial vanes as the vane edges are advanced into the article. This radial inward movement defeats the toroidal circulation as well as sometimes causing the articles to be drawn beneath the clearance space between the agitator and the basket bottom, which can severely degrade the fabric material.
To overcome such difficulties, it has heretofore been proposed to augment or supplant the water circulation systems with an agitator action causing movement of the clothing articles in a proper direction by direct contact of the agitator with the clothing articles. These designs have involved relatively complex and costly structures which increase significantly the cost of manufacturing the washing machine. The cost of such machines is a critical factor in a highly competitive market and this increase in cost is a very substantial drawback.
It is accordingly an object of the present invention to provide an arrangement for establishing a toroidal circulation of clothing articles in clothes washing machines of the type described which is capable of establishing such toroidal flow with relatively lean water/fabric ratios.
It is another object of the present invention to provide such an arrangement which is relatively simple and which does not substantially increase the cost of manufacturing the washing machines.
It is yet another object of the present invention to provide such an arrangement in which the tendency to chord the articles by rotation of the agitator vanes is substantially nullified.